A fighter of the Islamic State (formerly known as Isis) holds an Isis flag and a weapon on a street in the city of Mosul(Reuters)

An Anonymous-affiliated Twitter account has declared a "full-scale cyber war" against the Islamic State (formerly known as Isis) with the aim of tracking down members of the group throughout the world who "continue to use Twitter for propaganda".

The new Operation Ice ISIS campaign was launched over the weekend with a Twitter account declaring: "Welcome to Operation Ice #ISIS, where #Anonymous will do it's part in combating #ISIS's influence in social media and shut them down."

#Anonymous has declared a full-scale cyber war against #ISIS and their counterparts. We remind you that the Islamic State is not Islamic.

However as soon as the campaign was launched other members of the Anonymous collective voiced concerns that starting such a campaign could put members of Anonymous based in Syria and Iraq in danger.

Another influential Anonymous account - @YourAnonCentral - was among those strongly criticising the account, claiming that "people who have been friendly in the past or supportive of Anon can be targeted for it."

If you are pushing #OpIceISIS be ready to take responsibility for the deaths you are going to provoke.

While the account has retweeted a picture of what looks like an IS Twitter account being hacked by Anonymous, the account in question is in fact a parody account.

Commander X?

The account also posted a video claiming to show a member of IS taking part in the Ice Bucket Challenge, but this has also been showed to be a fake.

It is unclear who is behind the account though some suspected that it was Commander X (aka Christopher Doyon), a well-known member of the online movement who last year claimed to have quit Anonymous.

However this link has been denied by other accounts previously associated with Doyon.

Just as some parts of Anonymous begin a social media campaign against IS it is also reported that the US government is beginning a similar campaign to "win the war of ideas by ridiculing the militants with a mixture of blunt language and sarcasm."

Expose the facts

Speaking to AFP, a senior US State Department official described the strategy as a "cyber guerrilla campaign".

The source said: "It is not a panacea, it is not a silver bullet. People exaggerate, people think this is worthless or they think it a magic thing that will make the extremists surrender. It is neither one of those. It is slow, steady, daily engagement pushing back on a daily basis.

"It is a war of thousands of skirmishes, but no big battles. America likes big battles but it is not - it is like guerrilla warfare."

The US government has been engaging in this type of campaign for some time, but last week established a new Facebook page with a mission to "expose the facts about terrorists and their propaganda. Don't be misled by those who break up families and destroy their true heritage."